Rajendra Nath

Role of neuroinflammation and latent transcription factors in pathogenesis of Parkinson’s disease

Parkinson’s disease (PD) the second most common age-associated progressive neurodegenerative disorder is characterized by loss of dopaminergic neurons, cytoplasmic inclusions of aggregated proteins (Lewy bodies), and neuroinflammation. The inflammation of neurons causes release of various inflammatory mediators (IFNs, EGF, IL5, IL6, HGF, LIF and BMP2). The hallmarks of neuroinflammation are the presence of activated microglia and reactive astrocytes in the parenchyma of the CNS and increased production of cytokines, chemokines, prostaglandins, complement cascade proteins, and reactive oxygen and nitrogen species (ROS/RNS) which in some cases can result in disruption of the blood brain barrier and direct participation of the adaptive immune system. Latent transcription factors such as NF-κB, STAT 3, AP1, and SMAD 7, Toll like receptors and FAF 1 are constitutively upregulated in activated microglia. Toll-like receptors when activated promote NF-κB signaling thus promoting a vicious cycle of neuroinflammation. These transcription factors take dopaminergic neurons to apoptotic pathway via p53 and other death domain receptors. Neuroprotective signaling pathways such as mTOR, SOCS, and TGF-β down regulated during development of PD. YY1 signaling, which has protective effect against α-Synuclein toxicity, is significantly decreased in PD patients. In summary we can say that transcription factors promoting inflammation such as NF-κB, STAT 3, AP 1, and Toll-like receptors are constitutively upregulated in PD, while neuroprotective pathways such as mTOR, TGF-β, and YY1 are substantially downregulated in microglia of PD patients.

Design of potential siRNA molecules for hepatitis delta virus gene silencing.

Hepatitis D is a liable reason of mortality and morbidity worldwide. It is caused by an RNA virus known as Hepatitis Delta Virus (HDV). Genetic studies of HDV have shown that delta antigen protein is responsible for replication of genome and play a foremost role in viral infection. Therefore, delta antigen protein may be used as suitable target for disease diagnosis. Viral activity can be restrained through RNA interference (RNAi) technology, an influential method for post transcriptional gene silencing in a sequence specific manner. However, there is a genetic variability in different viral isolates; it is a great challenge to design potential siRNA molecules which can silence the respective target genes rather than any other viral gene simultaneously. In current study two effective siRNA molecules for silencing of HDV were rationally designed and validated using computational methods, which may lead to knockdown the activity of virus. Thus, this approach may provide an insight for the chemical synthesis of antiviral RNA molecule for the treatment of hepatitis D, at genome level.

Identification and Characterization of Novel Small-Molecule Inhibitors against Hepatitis Delta Virus Replication by Using Docking Strategies

Background The small delta antigen protein of hepatitis delta virus (HDV) has been shown to be important for replication of the virus and essential for the viral life cycle. Therefore, it may be an appropriate target for designing biological experiments for drug development to identify the potential inhibitors of hepatitis D. Objectives To identify a novel molecule as possible drug candidate for the treatment of Hepatitis D. Materials and Methods In the present study, a computational approach was used for the identification of novel small-molecule inhibitors against HDV replication using docking studies. An Autodock tool was used for docking and identifying the active binding sites in target proteins. The Lipinski filter and preADMET program were also used for determining the pharmacokinetic properties in order to filter out potential ligand molecules to restrain virus replication. Results Our results suggest that pyridinone (3-[(4,7-dichloro-1,3-benzoxazol-2-yl) methylamino]-5-ethyl-6-methyl-pyridin-2(1H)-one) is a validated potential inhibitor of HDV replication and could be as a novel antiviral drug for the treatment of hepatitis D. Counclusions We have identified a novel antiviral drug by using innovative computational approaches. The results provide a basis to experimentally develop into drug which can be used for the treatment of delta hepatitis.

Effects of a standardized Ayurvedic formulation on diabetes control in newly diagnosed Type-2 diabetics; a randomized active controlled clinical study

OBJECTIVES The purpose of this study was to investigate the efficacy of a standardized polyherbal formulation consists of aqueous extracts from six herbs, in patients with Type-2 diabetes mellitus. DESIGN Randomized, active control study. INTERVENTIONS 93 patients, newly diagnosed with Type-2 diabetes mellitus were randomly allocated to group 1 (received polyherbal capsules 500 mg/day, up titrated weekly to a maximum of 3 g/day) and group 2 (received Metformin 500 mg/day, up titrated weekly to a maximum of 2 g/day). MAIN OUTCOME MEASURES The primary endpoint was effect on the change from baseline in blood glucose (Fasting blood Glucose and Postprandial blood glucose), and glycosylated hemoglobin (HbA1c). The secondary outcome includes the effect on lipid levels, liver enzymes and renal function test. RESULTS After 24 weeks, mean laboratory measured fasting and post prandial blood glucose showed a decrease of 25.52% and 24.22% in polyherbal formulation (PHF) treated group, compared to 31.46% and 24% decrease in Metformin treated group (estimated treatment difference -10.8; 95% CI -22.63 to 1.03 and -0.36; -12.1 to 11.38, respectively). Reduction in HbA1c was also similar for PHF and Metformin (estimated treatment difference 0.01; 95% CI -0.51 to 0.53). However, the decrease in the mean total cholesterol level was more pronounced in PHF treated group (estimated mean difference 61.3; 95% CI 55.32 to 67.28) than Metformin treated group (estimated mean difference 41.12; 95% CI 34.92 to 47.32). Also, there was statistical significance between the treatment groups in total cholesterol level at the end of six months treatment (estimated treatment difference 20.18; 95% CI 12.34 to 28.02). CONCLUSION The study demonstrated that daily intake of this PHF decreased the glycemic level and improved lipid homeostasis, while maintaining the other serum biochemical levels to the normal, and therefore it may be useful for the patients with Type-2 diabetes. This trial is registered in the Clinical Trials Registry - India (CTRI) (CTRI/2014/03/004490).

Attenuation of lead neurotoxicity by supplementation of polyunsaturated fatty acid in Wistar rats

Background: Among various types of polyunsaturated fatty acid (PUFA), omega-3 fatty acids play a crucial role in development and function of the brain. This study was undertaken to investigate the possible neuroprotective efficacy of omega-3 fatty acid on lead-induced neurotoxicity in rats. Material and methods: The experiment was carried out on 32 male Wistar rats divided into four groups. The first group (control) was treated with distilled water and second group with lead acetate at the doses of 3 mg/kg b.wt. (body weight)/oral, whereas third and fourth groups were simultaneously treated with lead acetate (3 mg/kg b.wt.) plus omega-3 fatty acid (300 mg/kg b.wt./oral) and lead acetate (3 mg/kg b.wt.) plus vitamin E (100 mg/kg b.wt./oral), respectively, for a period of 90 days. Their biochemical and histopathological investigations have been carried out. Results: The level of lead was markedly elevated in brain (4.71-fold) and blood (5.65-fold), also increased levels of ROS, GSH, LPO with concomitant reduction in the activities of delta-ALAD, CAT, SOD, and GPx. In addition, lead-induced brain damage was indicated by histopathological changes. Omega-3 fatty acid resulted in marked improvement in most of the biochemical parameters as well as histopathological changes in rats. The results obtained were compared with vitamin E as the standard antioxidant agents. Discussion: Omega-3 fatty acid significantly (P < 0.05) decreased the effect of lead-induced brain damage as well as biochemical changes similar to that of standard drug, vitamin E. So, our result suggested that omega-3 fatty acid may play a protective role in lead-induced neurotoxicity and associated human health risk.

Molecular Docking studies of D2 Dopamine receptor with Risperidone derivatives.

In this work, 3D model of D2 dopamine receptor was determined by comparative homology modeling program MODELLER. The computed models energy was minimized and validated using PROCHECK and Errat tool to obtain a stable model structure and was submitted in Protein Model Database (PMDB-ID: PM0079251). Stable model was used for molecular docking against Risperidone and their 15 derivatives using AutoDock 4.2, which resulted in energy-based descriptors such as Binding Energy, Ligand Efficiency, Inhib Constant, Intermol energy, vdW + Hbond + desolv Energy, Electrostatic Energy, Total Internal Energy and Torsional Energy. After that, we have built quantitative structure activity relationship (QSAR) model, which was trained and tested on Risperidone and their 15 derivatives having activity value pKi in µM. For QSAR modeling, Multiple Linear Regression model was engendered using energy-based descriptors yielding correlation coefficient r2 of 0.513. To assess the predictive performance of QSAR models, different cross-validation procedures were adopted. Our results suggests that ligand-receptor binding interactions for D2 employing QSAR modeling seems to be a promising approach for prediction of pKi value of novel antagonists against D2 receptor.

Omega-3 fatty acid attenuates oxidative stress in cerebral cortex, cerebellum, and hippocampus tissue and improves neurobehavioral activity in chronic lead-induced neurotoxicity

Objectives: In view of the increasing risk of lead on human health, the present study has been carried out to investigate the neuroprotective effect of omega-3 fatty acid on chronic lead-induced neurotoxicity and behavioral impairment in rats. Methods: Different neurobehavioral parameters, biochemical assays, and histopathological analyses in brain regions of rats were conducted. Results: Rats exposed to different doses of lead (lead acetate 2.5, 5.0, 7.5 mg/kg body weight p.o. for 90 days) caused a significant decrease in body weight, brain weight, and behavioral changes as compared to controls. Abnormal histopathological and increased levels of lead in blood and brain regions increased the levels of ROS, LPO, PCC and decreased the levels of GSH with concomitant reduction in SOD, CAT, and GPx activities in the brain region of rats treated with different doses of lead as compared to controls. Co-treatment of lead with omega-3 fatty acid (500 mg/kg body weight p.o. for 90 days) decreased the levels of ROS, LPO, PCC, and increased the level of GSH, also increased SOD, CAT, and GPx activity and showed improvements in behavioral as well as histopathological changes as compared to lead-treated groups. Discussion: Our results proved that omega-3 fatty acid improved behavioral deficits, altered histopathological and oxidative stress in lead-intoxicated rats. Among three different doses, 2.5 mg/kg b.wt. of lead along with omega-3 fatty acid was the most preventive dose for the neurotoxicity. This work reveals the potential of omega-fatty acid as a protective drug for lead neurotoxicity.

Attenuation of Lead-Induced Neurotoxicity by Omega-3 Fatty Acid in Rats

Background: Lead is widely distributed in the environment and has been found to be associated with various health problems including neurodegenerative diseases. Purpose: In view of the increasing health risk caused by lead, this study has been carried out to investigate the neuroprotective effect of omega-3 fatty acid (omega-3FA) in lead-induced neurotoxicity in rats. Methods: Biochemical parameters including oxidative stress in brain regions, lead levels in blood and brain regions and histopathological examination of brain regions of rats were carried out in the present study. Results: Rats exposed to lead (lead acetate 7.5 mg/kg body weight p.o. for 14 days) caused a significant increase in the levels of lipid peroxidation, protein carbonyl content, ROS production and decreased the activities of glutathione peroxidase, superoxide dismutase and catalase in the cerebellum and cerebral cortex, respectively, as compared to controls. Abnormal histopathological changes and increase in the levels of lead in blood and brain were also observed as compared to controls. Co-treatment of lead with omega-3FA (750 mg/kg body weight p.o. for 14 days) decreased the levels of lipid peroxidation, protein carbonyl content, ROS production and increased the activities of glutathione peroxidase, superoxide dismutase and catalase and showed protection in the histopathological study as compared to rats treated with lead alone. Conclusions: The result of the present study shows that lead-induced oxidative stress and histopathological alteration in the brain region were significantly protected with co-treatment of lead and omega-3FA. This could be due to its strong antioxidant potential and metal-binding property.